The Role of Non-Invasive Multimodality Imaging in Chronic Coronary Syndrome: Anatomical and Functional Pathways

Randomised Placebo-Controlled Pilot Trial Evaluating the Anti-Anginal Efficacy of Ticagrelor in Patients with Angina with Nonobstructive Coronary Arteries and Coronary Slow Flow Phenomenon

Background: The coronary slow flow phenomenon (CSFP) is an angiographic finding characterised by the delayed passage of contrast through the coronary arteries, despite the absence of obstructive coronary artery disease (defined as less than 50% narrowing of the vessel lumen). Patients with the CSFP experience recurrent angina, for which there are limited evidence-based therapies. Ticagrelor may serve as an effective anti-anginal therapy for these patients by increasing adenosine levels, which could alleviate coronary microvascular dysfunction and its associated angina due to its vasodilatory properties. This study aimed to determine the anti-anginal efficacy of ticagrelor 90 mg taken twice daily on spontaneous angina episodes in patients with refractory angina (i.e., episodes ≥3/week despite two anti-anginals) and documented CSFP. Methods: In a randomised, double-blind, placebo-controlled, cross-over trial, the anti-anginal efficacy of a 4-week ticagrelor therapy regimen was evaluated in 20 patients with refractory angina (mean age 61.5 ± 10.5 years; 40% women) who had documented slow coronary flow. The primary endpoint was the frequency of angina episodes, recorded using an angina diary. Secondary endpoints included the duration and severity of angina episodes, consumption of short-acting nitrates, and health status evaluations using the Seattle Angina Questionnaire (SAQ) and the Short Form-36 (SF-36) indices. Results: During the four weeks of therapy, ticagrelor did not significantly improve angina symptoms compared to the placebo (placebo 25.7 (16.7)) vs. ticagrelor 19.8 (18.1), p > 0.05). Furthermore, it did not impact other patient-related outcome measures, including angina severity, duration, frequency of prolonged angina episodes, nitrate consumption, or the SAQ/SF-36 health outcome indices. No serious adverse events related to the study drug were observed. Conclusions: In patients with documented CSFP who were unresponsive to standard anti-anginal therapy, ticagrelor did not reduce the frequency of spontaneous angina episodes or the consumption of nitrates. Further confirmation of the potential benefits of this therapy may be obtained through a larger clinical trial.

Computed Tomography Angiography Identified High-Risk Coronary Plaques: From Diagnosis to Prognosis and Future Management

CT angiography has become, in recent years, a main evaluating modality for patients with coronary artery disease (CAD). Recent advancements in the field have allowed us to identity not only the presence of obstructive disease but also the characteristics of identified lesions. High-risk coronary atherosclerotic plaques are identified in CT angiographies via a number of specific characteristics and may provide prognostic and therapeutic implications, aiming to prevent future ischemic events via optimizing medical treatment or providing coronary interventions. In light of new evidence evaluating the safety and efficacy of intervening in high-risk plaques, even in non-flow-limiting disease, we aim to provide a comprehensive review of the diagnostic algorithms and implications of plaque vulnerability in CT angiography, identify any differences with invasive imaging, analyze prognostic factors and potential future therapeutic options in such patients, as well as discuss new frontiers, including intervening in non-flow-limiting stenoses and the role of CT angiography in patient stratification.

The Role of Magnetic Resonance Imaging in Risk Stratification of Patients with Acute Myocarditis

BACKGROUND

Cardiac magnetic resonance (cMRI) is often used to diagnose acute myocarditis (AM). It is also performed after 6 months to monitor myocardial involvement. However, the clinical and predictive relevance of the 6-month cMRI is uncertain.

OBJECTIVE

We used cMRI to assess the morphology and heart function of patients with AM, the correlation between left ventricular remodeling and biomarkers of heart dysfunction and myocardial fibrosis, and the involvement of myocardial fibrosis initially and 6 months after the acute episode.

MATERIALS AND METHODS

We conducted a prospective study of 90 patients with the clinical suspicion of AM, where cMRI was performed within the first week after symptom onset and repeated after 6 months.

RESULTS

Non-ischemic late gadolinium enhancement (LGE) was present in 88 (97.7%) patients and mainly involved the septum and inferior wall. cMRI at 6 months was associated with significantly reduced abnormalities of segmental kinetics (p < 0.001), myocardial edema (p < 0.001), presence of LGE (p < 0.05) and LGE mass (p < 0.01), native T1 mapping (p < 0.001), and presence of pericardial collection (p ≤ 0.001). At 6 months, signs of myocardial edema appeared in 34.4% of patients, and a complete cure (absence of edema and LGE) was found in 8.8% of patients. LGE disappeared in 15.2% of patients, and the mean number of myocardial segments involved decreased from 46% to 30%, remaining unchanged in 13% of patients. Patients with LGE without edema had a more severe prognostic condition than those with persistent edema. Patients with increased LGE extension on the control cMRI had a worse prognosis than those with modified or low LGE. The most significant independent predictive parameters for major cardiovascular events (MACEs) were LGE mass (adjusted OR = 1.27 [1.11-1.99], p < 0.001), myocardial edema (OR = 1.70 [1.14-209.3], p < 0.001), and prolonged native T1 (OR = 0.97 [0.88-3.06], p < 0.001). The mid-wall model of LGE and the presence of edema-free LGE were MACE-independent predictors.

CONCLUSIONS

LGE, myocardial edema, and prolonged native T1 were predictors of MACEs. LGE does not necessarily mean constituted fibrosis in the presence of edema and may disappear over time. LGE without edema could represent fibrosis, whereas the persistence of edema represents active inflammation and could be associated with the residual chance of complete recovery. cMRI should be performed in all patients with AM at 6 months to evaluate progress and prognosis.

Clinical impact of multimodality assessment of myocardial viability

Coronary artery disease (CAD) is a prevalent cause of left ventricular dysfunction. Nevertheless, effective elective revascularization, particularly surgical revascularization, can enhance long-term outcomes and, in selected cases, global left ventricular contractility. The assessment of myocardial viability and scars is still relevant in guiding treatment decisions and selecting patients who are likely to benefit most from blood flow restoration. Although the most recent randomized studies challenge the notion of "hibernating myocardium" and the clinical usefulness of assessing myocardial viability, the advancement of imaging techniques still renders this assessment valuable in specific situations. According to the guidelines of the European Society of Cardiology, non-invasive stress imaging may be employed to define myocardial ischemia and viability in patients with CAD and heart failure before revascularization. Currently, several non-invasive imaging techniques are available to evaluate the presence and extent of viable myocardium. The selection of the most suitable technique should be based on the patient, clinical context, and resource availability. This narrative review evaluates the characteristics of available imaging modalities for assessing myocardial viability to determine the most appropriate therapeutic strategy.

Cardiovascular Imaging for Coronary Artery Disease in Patients with Diabetes Mellitus

In patients with diabetes mellitus, accelerated progression of atherosclerosis can lead to worse clinical outcomes. Determining the best diagnostic strategy to identify patients with increased cardiovascular risk is challenging. Current guidelines recommend using both functional imaging and CT angiography to detect myocardial ischemia and coronary artery disease based on pre-test probability. Functional imaging is suggested for patients with a higher clinical likelihood due to its higher rule-in diagnostic capacity. On the other hand, CT angiography is preferred for patients with lower pre-test probability because of its excellent negative predictive value. The optimal management strategy for asymptomatic diabetic patients remains unclear. In asymptomatic diabetic patients, previous randomized trials have not shown benefits from diagnostic testing over standard care. However, these trials were methodologically inconsistent and lacked clear stratification of cardiovascular risk. In terms of invasive evaluation, a combined invasive functional and anatomic imaging approach for angiographically intermediate coronary stenosis appears to be the best, most effective decision pathway for managing diabetic patients.

Association between Epicardial Adipose Tissue and Atrial Fibrillation in Patients with Transfusion-Dependent β-Thalassemia

Background: Modern treatments for transfusion-dependent β-thalassemia (TDβT) have allowed patients to reach high life expectancy with no iron overload. Despite survival improvement, atrial fibrillation (AF) has emerged as a relevant issue. AF pathophysiology and characteristics in TDβT are different than in the general population. Epicardial adipose tissue (EAT) may play a role but its relationship with AF in patients with TDβT has not been explored. Methods: A monocentric, cross-sectional study, enrolling consecutive patients with TDβT. Epicardial adipose tissue (EAT) was evaluated at magnetic resonance. Characteristics of patients with and without history of AF were investigated. Factors independently associated with AF prevalence were analyzed. Results: A total of 116 patients were enrolled. All patients were treated with regular chelation therapy. The prevalence of AF was 29.3% (34/116). Cardiac T2* and liver iron concentration were no different between patients with and without AF. EAT thickness was significantly higher in patients with AF at left atrium, right atrium and right ventricle (5.0 vs. 4.0 mm, p < 0.01, 4.4 vs. 4.0, p = 0.02 and 5.0 vs. 4.3, p = 0.04). Patients with AF presented with older age, (53 vs. 49 years, p < 0.01), more hypothyroidism (44.1 vs. 20.7%, p = 0.01), pulmonary hypertension (23.5 vs. 2.4% p < 0.01), splenectomy (88.2 vs. 64.6%, p = 0.01), higher right and left atrial volume (61 vs. 40 and 74 vs. 43 mL, both p < 0.01). At multivariable analysis, hypothyroidism, left atrial volume and left atrial EAT were independently associated with AF (odds ratio 9.95, 1.09 and 1.91, respectively). Conclusions: In a contemporary cohort of patients with TDβT, treated with regular chelation therapy, prevalence of AF was unrelated to iron overload. EAT was independently associated with AF.

Cardiac CT: Competition, complimentary or confounder

Coronary CT angiography (CCTA) has been gradually adopted into clinical practice over the last two decades. CCTA has high diagnostic accuracy, prognostic value, and unique features such as assessment of plaque composition. CCTA-derived functional assessment techniques such as fractional flow reserve and CT perfusion are also available and can increase the diagnostic specificity of the modality. These properties propound CCTA as a competitor of functional testing in diagnosis of obstructive CAD, however, utilizing CCTA in a concomitant fashion to potentiate the performance of the latter can lead to better patient care and may provide more accurate prognostic information. Although multiple diagnostic challenges such as evaluation of calcified segments, stents, and small distal vessels still exist, the technologic developments in hardware as well as growing incorporation of artificial intelligence to daily practice are all set to augment the diagnostic and prognostic role of CCTA in cardiovascular disorders.

Comparison of the RF-CL and CACS-CL models to estimate the pretest probability of obstructive coronary artery disease and predict prognosis in patients with stable chest pain and diabetes mellitus

Background

The most appropriate tool for estimating the pretest probability (PTP) of obstructive coronary artery disease (CAD) in patients with diabetes mellitus (DM) and stable chest pain (SCP) remains unknown. Therefore, we aimed to validate and compare two recent models, namely, the risk factor-weighted clinical likelihood (RF-CL) model and coronary artery calcium score (CACS)-weighted clinical likelihood (CACS-CL) model, in these patient populations.

Methods

A total of 1,245 symptomatic patients with DM, who underwent CACS and coronary computed tomographic angiography (CCTA) scan, were identified and followed up. PTP of obstructive CAD for each patient was estimated using the RF-CL model and CACS-CL model, respectively. Area under the receiver operating characteristic curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were used to assess the performance of models. The associations of major adverse cardiovascular events (MACE) with risk groups were evaluated using Cox proportional hazards regression.

Results

Compared with the RF-CL model, the CACS-CL model revealed a larger AUC (0.856 vs. 0.782, p = 0.0016), positive IDI (12%, p < 0.0001) and NRI (34%, p < 0.0001), stronger association to MACE (hazard ratio: 0.26 vs. 0.38) and less discrepancy between observed and predicted probabilities, resulting in a more effective risk assessment to optimize downstream clinical management.

Conclusion

Among patients with DM and SCP, the incorporation of CACS into the CACS-CL model resulted in a more accurate estimation for PTP and prediction of MACE. Utilizing the CACS-CL model, instead of the RF-CL model, might have greater potential to avoid unnecessary and omissive cardiovascular imaging testing with minimal cost.

Screening for Subclinical Atherosclerosis and the Prediction of Cardiovascular Events in People with Type 1 Diabetes

People with type 1 diabetes (T1D) have a high cardiovascular disease (CVD) risk, which remains the leading cause of death in this population. Despite the improved control of several classic risk factors, particularly better glycaemic control, cardiovascular morbidity and mortality continue to be significantly higher than in the general population. In routine clinical practice, estimating cardiovascular risk (CVR) in people with T1D using scales or equations is often imprecise because much of the evidence comes from pooled samples of people with type 2 diabetes (T2D) and T1D or from extrapolations of studies performed on people with T2D. Given that T1D onsets at a young age, prolonged exposure to the disease and its consequences (e.g., hyperglycaemia, changes in lipid metabolism or inflammation) have a detrimental impact on cardiovascular health. Therefore, it is critical to have tools that allow for the early identification of those individuals with a higher CVR and thus be able to make the most appropriate management decisions in each case. In this sense, atherosclerosis is the prelude to most cardiovascular events. People with diabetes present pathophysiological alterations that facilitate atherosclerosis development and that may imply a greater vulnerability of atheromatous plaques. Screening for subclinical atherosclerosis using various techniques, mainly imaging, has proven valuable in predicting cardiovascular events. Its use enables the reclassification of CVR and, therefore, an individualised adjustment of therapeutic management. However, the available evidence in people with T1D is scarce. This narrative review provides and updated overview of the main non-invasive tests for detecting atherosclerosis plaques and their association with CVD in people with T1D.

Myocardial Late Gadolinium Enhancement (LGE) in Cardiac Magnetic Resonance Imaging (CMR)-An Important Risk Marker for Cardiac Disease

Cardiovascular magnetic resonance (CMR) has significantly revolutionized the comprehension and diagnosis of cardiac diseases, particularly through the utilization of late gadolinium enhancement (LGE) imaging for tissue characterization. LGE enables the visualization of expanded extracellular spaces in conditions such as fibrosis, fibrofatty tissue, or edema. The growing recognition of LGE's prognostic capacity underscores its importance, evident in the increasing explicit recommendations within guidelines. Notably, the contemporary characterization of cardiomyopathies relies on LGE-based scar assessment by CMR to a large extent. This review describes the pattern and prognostic value of LGE in detail for various cardiac diseases. Despite its merits, establishing LGE as a reliable risk marker encounters challenges. Limitations arise from the fact that not all diseases show LGE, and it should always be analyzed in the context of all CMR sequences and the patient's medical history. In summary, LGE stands as a robust indicator of adverse outcomes in diverse cardiovascular diseases. Its further integration into routine practice is desirable, necessitating widespread availability and application to accumulate both individual and scientific experience.

Myocardial strain of the left ventricle by speckle tracking echocardiography: From physics to clinical practice

Speckle tracking echocardiography (STE) is a reliable imaging technique of recognized clinical value in several settings. This method uses the motion of ultrasound backscatter speckles within echocardiographic images to derive myocardial velocities and deformation parameters, providing crucial insights on several cardiac pathological and physiological processes. Its feasibility, reproducibility, and accuracy have been widely demonstrated, being myocardial strain of the various chambers inserted in diagnostic algorithms and guidelines for various pathologies. The most important parameters are Global longitudinal strain (GLS), Left atrium (LA) reservoir strain, and Global Work Index (GWI): based on large studies the average of the lower limit of normality are -16%, 23%, and 1442 mmHg%, respectively. For GWI, it should be pointed out that myocardial work relies primarily on non-invasive measurements of blood pressure and segmental strain, both of which exhibit high variability, and thus, this variability constitutes a significant limitation of this parameter. In this review, we describe the principal aspects of the theory behind the use of myocardial strain, from cardiac mechanics to image acquisition techniques, outlining its limitation, and its principal clinical applications: in particular, GLS have a role in determine subclinical myocardial dysfunction (in cardiomyopathies, cardiotoxicity, target organ damage in ambulatory patients with arterial hypertension) and LA strain in determine the risk of AF, specifically in ambulatory patients with arterial hypertension.